/*
 * Copyright 2002-2010 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.googlecode.coss.common.utils.xml;

import java.util.Iterator;

import javax.xml.namespace.QName;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamWriter;

import org.xml.sax.Attributes;
import org.xml.sax.Locator;

import com.googlecode.coss.common.utils.lang.StringUtils;
import com.googlecode.coss.common.utils.lang.exception.Assert;

/**
 * SAX <code>ContentHandler</code> that writes to a <code>XMLStreamWriter</code>
 * .
 * 
 * @author Arjen Poutsma
 * @see XMLStreamWriter
 * @since 3.0
 */
class StaxStreamContentHandler extends AbstractStaxContentHandler {

    private final XMLStreamWriter streamWriter;

    /**
     * Constructs a new instance of the <code>StaxStreamContentHandler</code>
     * that writes to the given <code>XMLStreamWriter</code>.
     * 
     * @param streamWriter the stream writer to write to
     */
    StaxStreamContentHandler(XMLStreamWriter streamWriter) {
        Assert.notNull(streamWriter, "'streamWriter' must not be null");
        this.streamWriter = streamWriter;
    }

    public void setDocumentLocator(Locator locator) {
    }

    @Override
    protected void charactersInternal(char[] ch, int start, int length) throws XMLStreamException {
        streamWriter.writeCharacters(ch, start, length);
    }

    @Override
    protected void endDocumentInternal() throws XMLStreamException {
        streamWriter.writeEndDocument();
    }

    @Override
    protected void endElementInternal(QName name, SimpleNamespaceContext namespaceContext)
            throws XMLStreamException {
        streamWriter.writeEndElement();
    }

    @Override
    protected void ignorableWhitespaceInternal(char[] ch, int start, int length)
            throws XMLStreamException {
        streamWriter.writeCharacters(ch, start, length);
    }

    @Override
    protected void processingInstructionInternal(String target, String data)
            throws XMLStreamException {
        streamWriter.writeProcessingInstruction(target, data);
    }

    @Override
    protected void skippedEntityInternal(String name) {
    }

    @Override
    protected void startDocumentInternal() throws XMLStreamException {
        streamWriter.writeStartDocument();
    }

    @Override
    protected void startElementInternal(QName name, Attributes attributes,
                                        SimpleNamespaceContext namespaceContext)
            throws XMLStreamException {
        streamWriter.writeStartElement(name.getPrefix(), name.getLocalPart(),
                name.getNamespaceURI());
        if (namespaceContext != null) {
            String defaultNamespaceUri = namespaceContext.getNamespaceURI("");
            if (StringUtils.hasLength(defaultNamespaceUri)) {
                streamWriter.writeNamespace("", defaultNamespaceUri);
                streamWriter.setDefaultNamespace(defaultNamespaceUri);
            }
            for (Iterator<String> iterator = namespaceContext.getBoundPrefixes(); iterator
                    .hasNext();) {
                String prefix = iterator.next();
                streamWriter.writeNamespace(prefix, namespaceContext.getNamespaceURI(prefix));
                streamWriter.setPrefix(prefix, namespaceContext.getNamespaceURI(prefix));
            }
        }
        for (int i = 0; i < attributes.getLength(); i++) {
            QName attrName = toQName(attributes.getURI(i), attributes.getQName(i));
            if (!("xmlns".equals(attrName.getLocalPart()) || "xmlns".equals(attrName.getPrefix()))) {
                streamWriter.writeAttribute(attrName.getPrefix(), attrName.getNamespaceURI(),
                        attrName.getLocalPart(), attributes.getValue(i));
            }
        }
    }
}
